Stator winding of the electric motor of an elevator machine

ABSTRACT

Stator winding in the stator of the electric motor of an elevator machine, said stator comprising a stator frame ( 1 ) provided with stator teeth ( 11 ) and slots ( 12 ) between them, the stator winding ( 2 ) being fitted in said slots ( 12 ). The stator comprises a winding frame ( 3 ) having a bottom ( 31 ) facing against the slot and sides ( 32 ), in which winding frame the winding can be fitted, and it has strip-like or stick-like elements ( 4 ) of ferromagnetic material fitted at the mouths of the slots ( 12 ) to control the magnetic flux.

The present invention relates to a stator winding in the stator of theelectric motor of an elevator machine, said stator having a stator frameprovided with stator teeth and slots between them, the stator windingbeing fitted in said slots.

The stator of electric motors used in elevator machines consists of astator frame having stator teeth and stator slots between them, and astator winding arranged in the stator frame around the teeth. The statorframe may be laminated from thin plates forming a stator pack. Theconductors of the stator winding are placed directly in the stator slotse.g. as conductor bundles. The conductors are held in the slots by meansof slot wedges fitted at the upper edge of the slot. The slot wedges mayform a dovetail joint with the upper edge of the slot. A drawback withprior-art stators is a relatively slow and complicated winding process.

In addition, it is necessary to prevent conductor movements in the slotscaused by mechanical forces. For this purpose, it may be necessary toapply a sealant between the wedge and the conductors, or else each slotwedge is provided with an adapter piece having friction surfaces on itssides and two side pieces with corresponding friction surfaces on theirsides, as described e.g. in patent application FI-A-884154. Thesesolutions are also relatively complicated.

The object of the present invention is to achieve a new type of statorwinding structure that will allow a faster winding process. The mountingstructure of the invention is implemented using a plastic winding frameof e.g. trough-like shape, around which the stator winding is fitted.The winding frame comprises a slot stick, preferably of ferromagneticmaterial, adapted to the shape of the mouth of the slot. The slot stickcan be fastened securely by casting it fast on the winding frame. Theslot stick can be shaped freely. The features characteristic of thesolution of the invention are presented in detail in the claims below.

Since the slot stick is firmly fastened to the coil former, it is notpossible for the slot stick to be released. The invention makes itpossible to achieve a simple, fast and economical winding process,especially because the windings can be prepared as complete packs beforebeing mounted in the stator slots.

In the following, the invention will be described in detail by the aidof and example with reference to the attached drawings, wherein

FIG. 1 presents a stator according to the invention, comprising aplastic winding frame and a slot stick,

FIG. 2 presents another stator according to the invention with a plasticwinding frame for an electric motor, and

FIG. 3 presents a magnified view of detail A in FIG. 2.

FIG. 1 represents the stator of a cage induction motor used as anelevator hoisting motor. The stator consists of a stator frame 1 havingstator teeth 11 and stator slots 12 between them. The motor has a statorwinding (field pole coil) 2 placed around the stator tooth 11, woundaround a trough-like plastic winding frame 3, the bottom 31 of thewinding frame 3 being placed against the side face of the tooth 11. Thewinding frame 3 comprises a slot stick 4 made of ferromagnetic material,extending over the mouth of the slot and adapted to its shape, forcontrolling the magnetic flux. The slot stick has been cast inside thewinding frame 32 on one side of it, so the slot stick 5 is firmlyfastened in the winding frame and can not be detached. Before beingmounted on the stator slots 12, the windings 2 are fitted in the windingframes 3 to form complete winding packs and then mounted on the statorframe by pushing them into the slots 12.

FIGS. 2 and 3 illustrate a second embodiment of the invention, in whichthe bottom 31 of the winding frame 3 is provided with small elasticlocking tongues 33 projecting from the bottom. When the stator windingis being pushed into the slot 12, the locking tongues will snap in intoholes 13 provided in the slot of the stator frame. The locking elements33 thus prevent the field pole coil from moving out from the statorframe.

It is obvious to the person skilled in the art that differentembodiments of the invention are not limited to the example describedabove, but that they may be varied within the scope of the claimspresented below.

1. Stator winding in the stator of the electric motor of an elevatormachine, said stator comprising a stator frame provided with statorteeth and slots between them, the stator winding being fitted in saidslots, wherein the stator comprises a winding frame having a bottomplaced against the slot and sides, in which winding frame the windingcan be fitted, and that it comprises strip-like or stick-like elementsof ferromagnetic material fitted at the mouths of the slots forcontrolling the magnetic flux.
 2. Stator winding according to claim 1,wherein said elements are fitted inside the winding frame.
 3. Statorwinding according to claim 1, wherein said elements are shaped to followthe form of the mouth of the slot.
 4. Stator winding according to claim1, wherein the winding frame comprises flexible locking elementsprojecting from the bottom, which locking elements can be fitted intoholes provided in the slots and which, when the winding frame is beingpushed into the slot, are inserted into the holes and lock the windingframe and the stator winding to the stator frame.
 5. Stator windingaccording to claim 1, wherein the winding frame is substantiallytrough-like.
 6. Stator winding according to claim 1, wherein the windingframe is made of a plastic-like material.
 7. Stator winding according toin claim 1, wherein the locking elements are of the same material as thewinding frame.